Amplifier Assembly

ABSTRACT

An amplifier assembly includes a three or more way Doherty amplifier arrangement (DAA) having at least three amplifiers, including a main amplifier and at least two peak amplifiers. The DAA is within a dual-path package including a first-RF-input-lead and a second-RF-input-lead for receiving components of a split RF-input signal and providing the components to the DAA. A first-RF-output-lead and a second-RF-output-lead receive a split output signal from the DAA. The DAA includes a first-semiconductor-die and a second-semiconductor-die, each having thereon respective amplifier(s). The first-semiconductor-die includes a Doherty-splitter element splitting the RF-input signal from the first-RF-input-lead to provide an input to two amplifiers thereon and a Doherty-combiner element to combine an output from the two amplifiers. The Doherty-combiner element is connected to the first-RF-output-lead. The second-semiconductor-die amplifier(s) are connected to the second-RF-input-lead to provide an input to the amplifier(s) and to the second-RF-output-lead to receive an output from the amplifier(s).

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to European Patent Application No.15290194.8, filed Jul. 22, 2015, the contents of which is incorporatedby reference herein in its entirety.

BACKGROUND

The present disclosure relates to a Doherty based amplifier assembly andto an amplifier arrangement comprising a printed circuit board and theamplifier assembly. The disclosure also relates to a method offabricating the amplifier assembly and to an electronic device.

Doherty amplifiers are a type of amplifier that can be used for radiofrequency amplification. Doherty amplifiers have found particularapplication in the field of mobile telecommunications and are used inthe amplification of signals in GSM, WCDMA and LTE mobiletelecommunication networks and in particular in cellular base stations.

SUMMARY

According to a first aspect of the present disclosure there is providedan amplifier assembly comprising a three or more way Doherty amplifierarrangement having at least three amplifiers; a main amplifier and atleast two, further, peak amplifiers;

-   -   the Doherty amplifier arrangement mounted within a dual path        package having two RF input leads, comprising a first RF input        lead and a second RF input lead, configured to receive component        parts of a split RF input signal and to provide the component        parts to the Doherty amplifier arrangement and a first RF output        lead and a second RF output lead to receive a split output        signal from the Doherty amplifier arrangement and provide for        connection to further components;    -   the Doherty amplifier arrangement comprising a first        semiconductor die and a second semiconductor die, the first        semiconductor die having thereon two of the at least three        amplifiers and the second semiconductor die having thereon up to        two of the remaining amplifier or amplifiers of the at least        three amplifiers;        -   wherein the first semiconductor die includes a Doherty            splitter element configured to split an RF input signal            received from the first RF input lead to provide an input            signal to the two amplifiers thereon and a Doherty combiner            element to combine an output signal from the two amplifiers            thereon, the Doherty combiner element connected to the first            RF output lead; and    -   wherein the amplifier or amplifiers of the second semiconductor        die are connected to the second RF input lead to provide an        input signal to the amplifier or amplifiers and to the second RF        output lead to receive an output signal from the amplifier or        amplifiers of the second semiconductor die.

In one or more embodiments the amplifier arrangement may include threeamplifiers for forming a 3-way Doherty amplifier, the firstsemiconductor die including the main amplifier and one of the peakamplifiers; and

-   -   the second semiconductor die including a second peak amplifier.

In one or more embodiments the amplifier assembly optionally comprises athree or four way amplifier assembly. This arrangement is particularlyadvantageous in combination with a two RF path package or dual pathpackage.

In one or more embodiments the amplifier arrangement optionally includesfour amplifiers for forming a 4-way Doherty amplifier comprising themain amplifier and three peak amplifiers, the first semiconductor dieincluding the main amplifier and one of the peak amplifiers; and

-   -   the second semiconductor die including the remaining two peak        amplifiers, the second semiconductor die including a Doherty        splitter element configured to split an RF input signal received        from the second RF input lead to provide an input signal to the        two peak amplifiers thereon and a Doherty combiner element to        combine an output signal from the two peak amplifiers thereon,        the Doherty combiner element connected to the second RF output        lead.

In one or more embodiments the 3-way Doherty amplifier is optionally of1:2:1 type or 1.1:1 type.

In one or more embodiments the first semiconductor die optionallycomprises;

-   -   the main amplifier;    -   one of the peak amplifiers;    -   an output combination bar comprising the first RF output lead        configured to receive and combine an output from both the main        amplifier and the peak amplifier;    -   a main connection configured to connect an output of the main        amplifier to the combination bar, the main connection        comprising, at least in part, a bond wire forming a first        inductance;    -   a peak connection configured to connect an output of the peak        amplifier to the combination bar;    -   wherein the main connection connects to the combination bar at a        first point along the bar and the peak connection connects to        the combination bar at a second point along the bar spaced from        the first point and the main amplifier is located further from        the output combination bar than the peak amplifier stage.

In one or more embodiments the first semiconductor die optionallycomprises;

-   -   a first of the peak amplifiers;    -   a second of the peak amplifiers;    -   an output combination bar comprising the first RF output lead        configured to receive and combine an output from both the peak        amplifiers;    -   a first peak connection configured to connect an output of the        first of the peak amplifiers to the combination bar, the first        peak connection comprising, at least in part, a bond wire        forming a first inductance;    -   a second peak connection configured to connect an output of the        second of the peak amplifiers to the combination bar;    -   wherein the first peak connection connects to the combination        bar at a first point along the bar and the second peak        connection connects to the combination bar at a second point        along the bar spaced from the first point and the first of the        peak amplifiers is located further from the output combination        bar than the peak second peak amplifier stage.

In one or more embodiments the first and/or second semiconductor diesoptionally comprise Monolithic Microwave Integrated Circuits.

In one or more embodiments one or more of the main amplifier and the atleast two peak amplifiers optionally comprise multi-stage amplifiers.

According to a second aspect of the present disclosure there is providedan amplifier arrangement comprising;

-   -   a printed circuit board including        -   a packaged amplifier mounted thereon, the packaged amplifier            comprising the amplifier assembly of any preceding claim;        -   an RF input terminal connected to a splitter element            configured to split an RF input signal received at the RF            input terminal into at least two component parts and provide            those parts to the first RF input lead and second RF input            lead respectively of the packaged amplifier;        -   a Doherty combining element configured to combine the output            signals received from the first RF output lead and the            second RF output lead of the packaged amplifier and provide            the combined signal to an RF output terminal.

In one or more embodiments the printed circuit board optionally includesan output impedance matching network between the Doherty combiningelement and the RF output terminal for matching the impedance of a loadconnectable to the RF output terminal.

In one or more embodiments the printed circuit board optionally includesat least one phase delay element configured to provide a phase offsetbetween the RF input signals received by the first and second RF inputleads and/or provide a phase shift between the RF output signalsreceived from the first and second RF output leads.

According to a third aspect of the present disclosure there is provideda method for fabricating an amplifier assembly, the amplifier assemblycomprising a three or more way Doherty amplifier arrangement having atleast three amplifiers; a main amplifier and at least two, further, peakamplifiers comprising;

-   -   forming a dual path package having two RF input leads,        comprising a first RF input lead and a second RF input lead,        configured to receive component parts of a split RF input signal        and to provide the component parts to a Doherty amplifier        arrangement and a first RF output lead and a second RF output        lead to receive a split output signal from the Doherty amplifier        arrangement and provide for connection to further components,        including the step of;    -   providing a first semiconductor die and a second semiconductor        die for incorporation into the dual path package, the first        semiconductor die having thereon two of the at least three        amplifiers and the second semiconductor die having thereon up to        two of the remaining amplifier or amplifiers of the at least        three amplifiers;    -   connecting the first RF input lead to a Doherty splitter element        of the first semiconductor die, the Doherty splitter element        configured to split an RF input signal received from the first        RF input lead to provide an input signal to the two amplifiers        thereon and a Doherty combiner element to combine an output        signal from the two amplifiers thereon,    -   connecting the Doherty combiner element of the first        semiconductor die to the first RF output lead; and    -   connecting the amplifier or amplifiers of the second        semiconductor die to the second RF input lead to provide an        input signal to the amplifier or amplifiers and    -   connecting the amplifier or amplifiers of the second        semiconductor die to the second RF output lead to receive an        output signal from the amplifier or amplifiers of the second        semiconductor die.

According to a fourth aspect of the present disclosure there is providedan electronic device including the amplifier arrangement of the secondaspect.

In one or more embodiments the electronic device optionally comprises acellular base station.

While the disclosure is amenable to various modifications andalternative forms, specifics thereof have been shown by way of examplein the drawings and will be described in detail. It should beunderstood, however, that other embodiments, beyond the particularembodiments described, are possible as well. All modifications,equivalents, and alternative embodiments falling within the spirit andscope of the appended claims are covered as well.

The above discussion is not intended to represent every exampleembodiment or every implementation within the scope of the current orfuture Claim sets. The Figures and Detailed Description that follow alsoexemplify various example embodiments. Various example embodiments maybe more completely understood in consideration of the following DetailedDescription in connection with the accompanying Drawings.

BRIEF DESCRIPTION OF DRAWINGS

One or more embodiments will now be described by way of example onlywith reference to the accompanying drawings in which:

FIG. 1 shows an example embodiment of an amplifier assembly andamplifier arrangement;

FIG. 2 shows a second example of an amplifier assembly and amplifierarrangement;

FIG. 3 shows a schematic diagram of an example of the Doherty amplifierstructure of the first and or second semiconductor die;

FIG. 4 shows a flow chart illustrating the steps of fabricating anexample amplifier assembly;

FIG. 5 shows a cellular base station of a mobile telecommunicationnetwork incorporating the Doherty amplifier structure; and

FIG. 6 shows an example graph of efficiency (%) vs. output power.

DETAILED DESCRIPTION

Doherty amplifiers have been found to be advantageous for theirefficiency in particular applications, such as mobile base stationsamong others. In some examples, 3-way or 4-way (or n-way where n isgreater than 5) have been shown to have advantageous efficiencyparameters, such as at back-off. However, in practice, fabricating a 3or more way Doherty amplifier in a space efficient manner is difficult.There is a demand for 3 or more way Doherty amplifiers in small cellapplications in which small size is a requirement.

FIG. 1 shows a first example Doherty amplifier assembly 100 within adual path package 101. The packaged Doherty amplifier assembly 100 is,in this example, mounted on a printed circuit board or PCB 102 withadditional Doherty amplifier related circuitry.

The assembly 100 shown in FIG. 1 comprises a three way Doherty amplifierarrangement 103 having three amplifiers comprising a main amplifier 104,a first peak amplifier 105 and a second peak amplifier 106. The dualpath package has two RF input leads, comprising a first RF input lead107 and a second RF input lead 108, configured to receive parts of asplit, common RF input signal and to provide the component parts to theDoherty amplifier arrangement 103. The split RF signal is, in thisexample, received from a PCB mounted splitter element 110, which isconfigured to split an RF input signal received at an RF input terminal111 into two RF input signals for provision to the two RF input leads107, 108. The dual path package further comprises two output leads,comprising a first RF output lead 112 and a second RF output lead 113 toreceive output signals from different amplifiers or groups of amplifiers104, 105, 106 of the Doherty amplifier arrangement 103 and provide forconnection to further components, as will be described below. Thus, thefirst RF input lead 107 and the first RF output lead 112 form part of afirst path of the package 101 and the second RF input lead 108 and thesecond RF output lead 113 form part of a second path of the packagethereby defining the dual path package 101 with its two RF pathstherethrough.

The Doherty amplifier arrangement 103 is provided on two separatesemiconductor dies within the same package 101; a first semiconductordie 114 and a second semiconductor die 115. The components of the firstdie 114 form part of the first path and the components of the second dieform part of the second path. The first semiconductor die 114, hasthereon two of the three amplifiers 104, 105, 106 comprising, in thisexample, the main amplifier 104 and the first peak amplifier 105. Thesecond semiconductor die 115 has thereon the remaining amplifier, thesecond peak amplifier 106, in this example.

Thus, the first semiconductor die 114 provides a two way Dohertyamplifier arrangement and the second semiconductor die 115 provides aone way amplifier, which together form a three way Doherty amplifierarrangement 103. In other embodiments the second die 115 may provide atwo way Doherty amplifier as well as the first die 114 and thereforetogether the dies 114, 115 form a four way Doherty amplifier, as will bedescribed later with reference to FIG. 2.

With reference to FIG. 1, the first semiconductor die 113 includes aDoherty splitter element 116 configured to split the (already split bysplitter element 110) RF input signal received from the first RF inputlead 107 to provide an input signal to the two amplifiers 104, 105thereon and a Doherty combiner element 117 to combine output signalsfrom the two amplifiers thereon, the Doherty combiner element configuredto provide the combined signal to the first RF output lead 112.

The second peak amplifier 106 of the second semiconductor die 115 isconnected to the second RF input lead 108 to provide an input signal tothe second peak amplifier 106. The second peak amplifier 106 of thesecond semiconductor die 115 provides its output signal to the second RFoutput lead 113.

This arrangement is advantageous as the Doherty splitting and Dohertycombining elements of two of the amplifiers (along with the amplifiersthemselves) are provided on one of semiconductor dies 114 and the othersemiconductor die 115 may comprise a conventional discrete amplifier106. The combination of these two dies in a single package has beenfound to be highly compact. The packaged 3-way amplifier has dual pathinput/output making it easier to handle as the terminals 107, 108, 112,113 may be wider for a given size of package 101 compared to a three ormore path package. The splitting and combination of input and outputsignals for provision to and receiving from the two paths of the packagemay be provided external to the package on the PCB 102, as will bediscussed further below. Thus, only a two-way splitter element 110 and atwo way combiner element 118 is required on the PCB 102 to form, withthe package 101, a three way Doherty amplifier between the RF inputterminal 111 and an RF output terminal 120.

The amplifiers 104, 105 of the first semiconductor die 114 and theamplifier of the second semiconductor die may each be associated (oronly one of them) with an input side matching elements (not shown). Theinput matching elements may form part of the first and second dies 114,115 respectively or may be provided on the PCB 102 between the splitterelement 110 and the first and second RF input leads 107, 108respectively. The input matching elements may comprise a network ofcapacitances and inductances or transmission lines, as will be known tothose skilled in the art. In other embodiments, the components of thefirst and second semiconductor dies 114, 115 may be input matchedobviating the need for distinct input-side matching networks. The inputmatching elements may provide for phase compensation between theamplifiers 104, 105 of the first semiconductor die 114 and the amplifierof the second semiconductor die, as necessary for the arrangement of theamplifiers that form the Doherty amplifier.

Further, on an output side of the package 101, one or more outputmatching elements 121 may be provided on the PCB between the first andsecond RF output leads 112, 113 and the combiner element 118. The outputmatching elements may comprise a network of capacitances and inductancesor transmission line(s), as will be known to those skilled in the art.Further an impedance invertor 122, which may comprise a quarter wavetransmission line, may be provided adjacent the combiner element 118.The PCB 102 may also include an output impedance matching element toprovide a transformation from the impedance of the 3-way amplifier to aload 123. It will be appreciated that the output impedance matchingelement may be located in element 121 (or a counterpart for the peakamplifier), or in between the combiner element 118 and the output load123, or in both of the above.

This embodiment comprises a 1:2:1 type three way Doherty amplifier,although the same principles can be applied to a 1:1:1 type or othertype. It will be appreciated that whether the first peak or second peakamplifier is located on the same die as the main amplifier may only havea practical implication if there is a difference in the amplificationfactor between the first and second peak amplifiers, as there would bein a 1:2:1 arrangement.

FIG. 2 shows a second example of a Doherty amplifier assembly 200 withina dual path package 201 similar to the first example of FIG. 1 and thesame reference numerals have been used for like parts but increased by100. The main difference is that the assembly 200 shown in FIG. 2comprises a four way Doherty amplifier arrangement rather than a threeway Doherty amplifier arrangement.

The four way Doherty amplifier arrangement has four amplifierscomprising a main amplifier 204, a first peak amplifier 205, a secondpeak amplifier 206 and a third peak amplifier 209.

Similar to the first example, the four way Doherty amplifier arrangement203 is provided on two separate semiconductor dies within the samepackage 201; a first semiconductor die 214 and a second semiconductordie 215. Thus the components of the first die 214 form part of the firstpath and the components of the second die 215 form part of the secondpath. The first semiconductor die 214, has thereon two of the fouramplifiers 204, 205, comprising, in this example, the main amplifier 204and the first peak amplifier 205. The second semiconductor die 115 hasthereon the remaining two amplifiers, the second peak amplifier 206 andthe third peak amplifier 209, in this example.

Thus, the first semiconductor die 214 provides a two way Dohertyamplifier arrangement and the second semiconductor die 215 provides atwo way amplifier, which together form a four way Doherty amplifierarrangement 203.

The first semiconductor die 213 includes a Doherty splitter element 216configured to split the (already split by splitter element 210) RF inputsignal received from the first RF input lead 207 to provide an inputsignal to the two amplifiers 204, 205 thereon and a Doherty combinerelement 217 to combine output signals from the two amplifiers thereon,the Doherty combiner element configured to provide the combined signalto the first RF output lead 212. Likewise, the second semiconductor die214 includes a Doherty splitter element 224 configured to split the(already split by splitter element 210) RF input signal received fromthe second RF input lead 208 to provide an input signal to the twoamplifiers 206, 209 thereon and a Doherty combiner element 225 tocombine output signals from the two amplifiers thereon, the Dohertycombiner element 225 configured to provide the combined signal to thesecond RF output lead 213.

On the PCB 202, the output side includes a first output matching element226, which may comprise a quarter wave transmission line, between thefirst RF output lead 212 and the combiner element 218. Further, a secondoutput matching element 227, which may comprise a quarter wavetransmission line, is provided between the second RF output lead 213 andthe combiner element 218. The output matching elements 226, 227 mayperform impedance matching to transform the output impedance of thefirst and second semiconductor dies 214, 215 to the desired value level.An impedance inverter element 222, which may comprise a quarter wavetransmission line, may be provided adjacent the combiner element 218.The PCB 202 may also include an output impedance matching element 228 toprovide a transformation from the impedance of the 4-way Dohertyamplifier to the load 223.

FIG. 3 shows an example Doherty amplifier structure 300 that may be usedfor a semiconductor die 301, such as semiconductor die 114 of FIG. 1 orsemiconductor dies 214, 215 of FIG. 2, that contains two of the three ormore amplifiers that form an n-way Doherty amplifier. For example, amain and peak amplifier or a first peak and a second peak amplifier. Thefollowing example shows a main and a peak amplifier although a similarstructure may be used for a peak/peak amplifier. Thus, the semiconductordie 301 may comprise the first or second semiconductor dies 114, 115,214, 215 described above depending how the main and peak amplifiers arearranged in practice. The input lead 302 comprises the first RF inputlead or the second RF input lead, which forms part of the package 101,201 (shown in FIGS. 1 and 2) and supplies an input signal to the Dohertyamplifier structure 300. The output lead 303 comprises the first RFoutput lead or the second RF output lead, which forms part of thepackage 101, 201 and comprises an output for the output signal that hasbeen amplified by the Doherty amplifier structure 300.

The integrated Doherty amplifier structure 300 comprises the mainamplifier 304 that is connected in parallel with the peak amplifier 305.The peak amplifier 305 is configured to receive an input signal that isphase delayed with respect to the input signal received by the mainamplifier stage 304, as will be discussed in more detail below. The mainand peak amplifiers are provided by field effect transistors or bipolartransistors and thus have source, gate and drain connections. The mainand peak amplifier stages may comprise cascaded stage amplifiersincluding a driver transistor(s) and a final transistor. An inputsplitting element 307 is configured to split the input signal from theinput lead 302 to the main and peak amplifiers 304, 305. The inputsplitting element 307 comprises an integrated element on the die 301 andreceives the input signal via a bond wire 306.

The main amplifier 304 receives an input signal directly from the inputsplitting element 307. An integrated, phase compensation element 308receives the signal from the input splitting element 307 and provides aphase shifted signal to a gate 309 of the peak amplifier 305. The phasecompensation element 308 may be implemented in any known manner, such asan appropriate network of capacitances and inductances. The phasecompensation element 308 compensates for phase delays between the outputof the main and peak amplifier stages caused by an impedance inversionarrangement, as will be described in more detail below.

The output lead 303 is arranged to receive an output from the mainamplifier 304 and the peak amplifier 305. The output lead 303 forms acombination bar in the structure 300. The output 312 of the mainamplifier 304 is connected to the output lead 303 by a main connection313, formed by a bond wire. The output 314 of the peak amplifier 305 isconnected to the output lead 303 by a peak connection 315, formed by abond wire. The physical length and electrical length of the mainconnection 313 is greater than the physical and electrical length ofeach of the peak connection 315. The combination bar has a width and isorientated such relative to the main and peak amplifier that the mainand peak connection bond wires can be constructed parallel to oneanother and combine at the combination bar at spaced locations along itswidth. In particular, the combination bar extends perpendicular to thebond wires that attach to it. In this embodiment, the combination barcomprises the edge of the output lead 303.

The different lengths of the main connection 313 compared to the peakconnection 315 in combination with output parasitic capacitances of themain and peak amplifiers 304, 305 form an impedance inverterarrangement. The impedance inversion arrangement is tuned such that theoutput from the main amplifier 304 can be efficiently received at theoutput lead 303 when only the main amplifier stage is operating and theoutput of the main and peak amplifiers can be efficiently received andcombined at the output lead 303.

The impedance inversion arrangement introduces approximately a 90° phaseshift in the output of the main amplifier 304 and therefore the phasecompensation element 308 are adapted to compensate for this phase shift.Accordingly, the output from the main amplifier 304 and the peakamplifier 305, when operating together, at high power, are combined atthe output lead 303 in phase. The peak connection 315 is preferablyshort and therefore the output of the peak amplifier is located adjacentthe die edge so that the bond wires that connect the output from thepeak amplifiers to the output lead are short and introduce a small,preferably minimal, phase shift.

Further input leads may be present to connect the die 301 to otherinputs required by the Doherty amplifier structure, such as to provide agate bias and drain bias, for the main and peak amplifier stages 304,305. Such inputs will be known to those skilled in the art.

The position of the main amplifier 304 in the die 301 relative to thepeak amplifier 305 enables a longer bond wire 313 to be used. The use ofthe longer bond wire between the main amplifier and the combinationpoint at the output lead is advantageous because the larger inductanceof the main bond wire can be used in part to form an impedance inversionarrangement.

The above described embodiment achieves high levels of integration asthe Doherty amplifier structure can be formed on a die in which theinput splitting element is integrated, the phase compensation network isintegrated, the amplifier stages are integrated and the impedanceinversion network is formed, in part, by bond wires that also providethe connection from the die to an output lead. The locating of the mainamplifier stage further from the output lead than the peak amplifierstage provides the space for the main connection bond wire to extendparallel to the peak connection bond wire while having the electricallength to implement an impedance inversion arrangement between theamplifier stages and the output lead. As the bond wires comprise theonly non-integrated part of the impedance inversion arrangement, theDoherty amplifier structure is reliable to manufacture and easy to tune.

FIG. 4 shows a flow chart illustrating an example method for fabricatingan amplifier assembly. The step of forming or receiving a pre-formeddual path package having two RF input leads, comprising a first RF inputlead and a second RF input lead, configured to receive component partsof a split RF input signal and to provide the component parts to aDoherty amplifier arrangement and a first RF output lead and a second RFoutput lead to receive a split output signal from the Doherty amplifierarrangement and provide for connection to further components is shown asstep 401. The step of providing a first semiconductor die and a secondsemiconductor die for incorporation into the dual path package, thefirst semiconductor die having thereon two of the at least threeamplifiers and the second semiconductor die having thereon up to two ofthe remaining amplifier or amplifiers of the at least three amplifiersis shown as step 402. Connecting the first RF input lead to a Dohertysplitter element of the first semiconductor die, the Doherty splitterelement configured to split an RF input signal received from the firstRF input lead to provide an input signal to the two amplifiers thereonand a Doherty combiner element to combine an output signal from the twoamplifiers thereon is shown as step 403. The step of connecting theDoherty combiner element of the first semiconductor die to the first RFoutput lead is shown at 404. The step of connecting the amplifier oramplifiers of the second semiconductor die to the second RF input leadto provide an input signal to the amplifier or amplifiers is shown atstep 405. Connecting the amplifier or amplifiers of the secondsemiconductor die to the second RF output lead to receive an outputsignal from the amplifier or amplifiers of the second semiconductor dieis shown at step 406. It will be appreciated that steps 403, 404, 405,406 can be performed in any order.

FIG. 5 shows a cellular base station 500 of a mobile telecommunicationnetwork incorporating the Doherty amplifier assembly 100, 200. TheDoherty amplifier assembly 100, 200 is used to amplify a signal used todrive the antenna 501.

FIG. 6 shows efficiency (%) vs. output power, Pout (dBm) responses forDoherty amplifier assembly of FIG. 1, shown as line 601 and known 2:1asymmetric MMIC of the same power capability 602.

The instructions and/or flowchart steps in the above Figures can beexecuted in any order, unless a specific order is explicitly stated.Also, those skilled in the art will recognize that while one example setof instructions/method has been discussed, the material in thisspecification can be combined in a variety of ways to yield otherexamples as well, and are to be understood within a context provided bythis detailed description.

In some example embodiments the set of instructions/method stepsdescribed above are implemented as functional and software instructionsembodied as a set of executable instructions which are effected on acomputer or machine which is programmed with and controlled by saidexecutable instructions. Such instructions are loaded for execution on aprocessor (such as one or more CPUs). The term processor includesmicroprocessors, microcontrollers, processor modules or subsystems(including one or more microprocessors or microcontrollers), or othercontrol or computing devices. A processor can refer to a singlecomponent or to plural components.

In other examples, the set of instructions/methods illustrated hereinand data and instructions associated therewith are stored in respectivestorage devices, which are implemented as one or more non-transientmachine or computer-readable or computer-usable storage media ormediums. Such computer-readable or computer usable storage medium ormedia is (are) considered to be part of an article (or article ofmanufacture). An article or article of manufacture can refer to anymanufactured single component or multiple components. The non-transientmachine or computer usable media or mediums as defined herein excludessignals, but such media or mediums may be capable of receiving andprocessing information from signals and/or other transient mediums.

Example embodiments of the material discussed in this specification canbe implemented in whole or in part through network, computer, or databased devices and/or services. These may include cloud, internet,intranet, mobile, desktop, processor, look-up table, microcontroller,consumer equipment, infrastructure, or other enabling devices andservices. As may be used herein and in the claims, the followingnon-exclusive definitions are provided.

In one example, one or more instructions or steps discussed herein areautomated. The terms automated or automatically (and like variationsthereof) mean controlled operation of an apparatus, system, and/orprocess using computers and/or mechanical/electrical devices without thenecessity of human intervention, observation, effort and/or decision.

It will be appreciated that any components said to be coupled may becoupled or connected either directly or indirectly. In the case ofindirect coupling, additional components may be located between the twocomponents that are said to be coupled.

In this specification, example embodiments have been presented in termsof a selected set of details. However, a person of ordinary skill in theart would understand that many other example embodiments may bepracticed which include a different selected set of these details. It isintended that the following claims cover all possible exampleembodiments.

We claim:
 1. An amplifier arrangement comprising: a printed circuitboard including: an RF input terminal; an RF output terminal; a packagedamplifier mounted thereon, said packaged amplifier having a first RFinput lead, a second RF input lead, a first RF output lead, and a secondRF output lead, and comprising an amplifier assembly; a splitter elementconnected to the RF input terminal and configured to split an RF inputsignal received at the RF input terminal into at least two componentparts and provide those parts to the first RF input lead and second RFinput lead, respectively, of the packaged amplifier; a Doherty combiningelement configured to combine the output signals received from the firstRF output lead and the second RF output lead of the packaged amplifierand provide the combined signal to the RF output terminal; and animpedance invertor element arranged adjacent to said Doherty combiningelement; wherein the amplifier assembly comprises: a dual path packagehaving said first RF input lead, said second RF input lead, said firstRF output lead, and said second RF output lead; a three or more wayDoherty amplifier arrangement having at least three amplifiers, the atleast three amplifiers including a main amplifier and at least two peakamplifiers; the Doherty amplifier arrangement mounted within the dualpath package, wherein the first RF input lead and the second RF inputlead are configured to receive the component parts of the split RF inputsignal and to provide the component parts to the Doherty amplifierarrangement, and wherein the first RF output lead and the second RFoutput lead are configured to receive the split output signal from theDoherty amplifier arrangement and to provide for connection to furthercomponents; the Doherty amplifier arrangement comprising a firstsemiconductor die and a second semiconductor die, the firstsemiconductor die having thereon two of the at least three amplifiersand the second semiconductor die having thereon up to two of theremaining amplifier or amplifiers of the at least three amplifiers;wherein the first semiconductor die includes a Doherty splitter elementconfigured to split the RF input signal received from the first RF inputlead to provide an input signal to the two amplifiers thereon and aDoherty combiner element to combine an output signal from the twoamplifiers thereon, the Doherty combiner element connected to the firstRF output lead; wherein the amplifier or amplifiers of the secondsemiconductor die are connected to the second RF input lead to providean input signal to the amplifier or amplifiers and to the second RFoutput lead to receive an output signal from the amplifier or amplifiersof the second semiconductor die; and wherein the splitter element, theDoherty combining element, and the impedance invertor are mounted on theprinted circuit board external of the packaged amplifier.
 2. Theamplifier arrangement according to claim 1, wherein the amplifierarrangement includes three amplifiers for forming a 3-way Dohertyamplifier, the first semiconductor die including the main amplifier andone of the peak amplifiers; and the second semiconductor die including asecond peak amplifier.
 3. The amplifier arrangement according to claim1, wherein the amplifier assembly comprises a three or four way Dohertyamplifier assembly.
 4. The amplifier arrangement according to claim 1,wherein the amplifier arrangement includes four amplifiers for forming a4-way Doherty amplifier comprising the main amplifier and three peakamplifiers, the first semiconductor die including the main amplifier andone of the peak amplifiers; and the second semiconductor die includingthe remaining two peak amplifiers, the second semiconductor dieincluding a Doherty splitter element configured to split an RF inputsignal received from the second RF input lead to provide an input signalto the two peak amplifiers thereon and a Doherty combiner element tocombine an output signal from the two peak amplifiers thereon, theDoherty combiner element connected to the second RF output lead.
 5. Theamplifier arrangement according to claim 2, wherein the 3-way Dohertyamplifier is of 1:2:1 type or 1:1:1 type.
 6. The amplifier arrangementaccording to claim 3, wherein the 3-way Doherty amplifier is of 1:2:1type or 1:1:1 type.
 7. The amplifier arrangement according to claim 1,wherein the first semiconductor die comprises: the main amplifier; oneof the peak amplifiers; an output combination bar comprising the firstRF output lead configured to receive and combine an output from both themain amplifier and the peak amplifier; a main connection configured toconnect an output of the main amplifier to the combination bar, the mainconnection comprising, at least in part, a bond wire forming a firstinductance; a peak connection configured to connect an output of thepeak amplifier to the combination bar; wherein the main connectionconnects to the combination bar at a first point along the bar and thepeak connection connects to the combination bar at a second point alongthe bar spaced from the first point and the main amplifier is locatedfurther from the output combination bar than the peak amplifier stage.8. The amplifier arrangement according to claim 1, wherein the firstsemiconductor die comprises: a first of the peak amplifiers; a second ofthe peak amplifiers; an output combination bar comprising the first RFoutput lead configured to receive and combine an output from both thepeak amplifiers; a first peak connection configured to connect an outputof the first of the peak amplifiers to the combination bar, the firstpeak connection comprising, at least in part, a bond wire forming afirst inductance; a second peak connection configured to connect anoutput of the second of the peak amplifiers to the combination bar;wherein the first peak connection connects to the combination bar at afirst point along the bar and the second peak connection connects to thecombination bar at a second point along the bar spaced from the firstpoint and the first of the peak amplifiers is located further from theoutput combination bar than the peak second peak amplifier stage.
 9. Theamplifier arrangement according to claim 1, wherein the first and/orsecond semiconductor dies comprise Monolithic Microwave IntegratedCircuits.
 10. The amplifier arrangement according to claim 1, whereinone or more of the main amplifier and the at least two peak amplifierscomprise multi-stage amplifiers.
 11. The amplifier arrangement accordingto claim 1 wherein the printed circuit board includes an outputimpedance matching network between the Doherty combining element and theRF output terminal for matching the impedance of a load connectable tothe RF output terminal.
 12. The amplifier arrangement according to claim1 wherein the printed circuit board includes at least one phase delayelement configured to provide a phase offset between the RF inputsignals received by the first and second RF input leads and/or provide aphase shift between the RF output signals received from the first andsecond RF output leads.
 13. An electronic device including the amplifierarrangement of claim
 1. 14. An electronic device of claim 13, whereinthe electronic device comprises a cellular base station.